1. Field of the Invention
The present invention relates generally to computer-assisted design of models and, more specifically, to a system and method of interactively assembling a geometric model for use in Computer-Aided Engineering analysis.
2. Description of the Related Art
Vehicle design, and in particular automotive vehicle design, has advanced to a state in which computer-assisted design techniques are frequently incorporated in the development of a new vehicle, or redesign of an existing vehicle. At the same time, enhanced visualization software tools have been developed that allow for interactive display and manipulation of large-scale geometric models, including models developed using Computer-Aided Design (CAD). The combined use of Computer-Aided Design and visualization techniques is especially beneficial in designing, packaging and assembling various proposals into a vehicle model, to evaluate the design and functional capabilities of the vehicle model. Advantageously, potential vehicle model designs can be considered in a timely and cost-effective manner by analyzing a digital representation of a proposed design, versus preparing a physical prototype of the vehicle.
One aspect of the design process is to construct a geometric model of the proposed design using a technique known as Computer-Aided Design (CAD). Another aspect of the design process is the use of mathematical tools, collectively referred to as Computer-Aided Engineering (CAE), to constrain and guide the designer in evaluating the design and to optimize the performance of the design. The use of a CAE simulation allows for verification of a design intent, and a prediction of a mechanical behavior of the design, including its systems, subsystems and components, and suggestion for improvement. CAE simulations are advantageous in particular types of vehicle analysis, such as vehicle analysis. Examples of CAE techniques include Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD). Various software tools are available to perform the CAE analysis. Recent enhancements to the software and the computing power of modern computers have resulted in a reduction in the amount of computer processing time required to perform the CAE analysis. Therefore, CAE tools can be utilized earlier in the design process and applied to a wider range of product development activities.
Vehicles, and in particular motor vehicles, are subject to regulations. Current practice relies on various methods to evaluate a proposed design. A physical “buck” or prototype may be utilized to provide information regarding the proposed design. A physical experiment may be performed using the physical prototype. It is time consuming to build the physical model, or to reconstruct the model after a test. An emerging trend in the vehicle design process, as a result of enhanced CAE computational capabilities, is the use of CAE analysis to predict how a particular vehicle design will respond when subjected to a predetermined test.
In particular, an initial evaluation of a design may be performed using a CAE simulation and a geometric mesh model. The engineer prepares the geometric mesh model for use in the CAE simulation corresponding to variations in a set of predetermined design parameters. As a result, tests may be conducted in earlier phases of the product development process, and proposed modifications to the design can be expeditiously analyzed. For example, a CAE analysis may provide the engineer with information regarding the integrity of the exterior shape of the vehicle, which is useful in the design of the exterior shape of a vehicle.
The validity of such a computer-assisted analysis is dependent on the quality of the geometric model. In turn, the quality of the model is dependent on various factors, including the skill and expertise of the modeler in assembling the model. Currently, the modeler manually integrates available software tools with engineering knowledge and best practice guidelines to assemble the geometric model. For example, the modeler may select a CAD model of component parts to be included in the assembled geometric model. The modeler may also select predetermined criteria relating to the model, as set forth in a best practice guideline available to the modeler. For a CAE analysis, a best practice guideline is utilized. The modeler may also select how to geometrically model a particular component. For example, a hinge may be modeled as a spring or a rigid body. Similarly, a spot weld may be modeled as a rigid element or a spring. These decisions influence the quality of the assembled model, and are dependent on the ability of the modeler.
While the current method works in assembling a model, there may be inconsistencies between models, which affect the overall integrity of the model. As a result, the information learned from a test using the assembled geometric model might not correlate well with the results of a test using a physical prototype. Also, there may be poor correlation between geometric models assembled by different modelers. Thus, there is a need in the art for a system and method of automatically assembling a geometric model for use in a Computer-Aided Engineering analysis that consistently generates a quality model, irrespective of the skill of the modeler.